Coupling device

ABSTRACT

The invention relates to a coupling device for drill rods comprising a receiving socket for receiving a connecting portion of the drill rod. Provision is made for at least one locking device with a locking element, which is supported in an adjustable manner between a release position and a locking position, in which the locking element engages into a corresponding recess of the connecting portion.

The invention relates to a coupling device for drill rods, in particularfor earth drilling apparatuses.

It is known to mutually connect single drill strings of a drill rod bymeans of screw bolts. This provides a reliable and stable rotationalconnection. In the same way a connection of the drill rod to a drilldrive is brought about. However, this kind of connection proves to bevery time consuming.

The invention is based on the object to provide a coupling device fordrill rods, by means of which both a quick and reliable connection canbe produced.

The object is solved in accordance with the invention by a couplingdevice having the features of claim 1. Preferred embodiments areindicated in the dependent claims.

The coupling device for drill rods according to the invention comprisesa receiving socket for receiving a connecting portion of a drill rod,wherein a locking device with a locking element is provided, which issupported in an adjustable manner between a release position and alocking position, in which the locking element engages into acorresponding recess of the connecting portion. With the coupling deviceaccording to the invention a quick semi-automatic or fully automaticcoupling with a drill rod is rendered possible. As a result, the workingoperation during drilling is facilitated and accelerated.

A preferred embodiment of the invention resides in the fact that thelocking device has a housing arranged on the outer side of the receivingsocket and in that a sliding element is supported in the housing foradjusting the locking element. In this way a stable and reliableoperation of the coupling device according to the invention is achieved.

The sliding element can be operated manually or by an operable adjustingmember, such as a motor or an adjusting cylinder.

In accordance with the invention a particularly advantageous embodimentresults from the fact that the sliding element is designed as apivotably supported bolt having a cam, which engages into an obliquelyextending slotted link in the housing. Through this cam mechanism aturning movement can be transformed into an axial adjusting movement.This mechanism allows for a good force application even in manualoperation.

To this end it is preferred according to the invention that a pivotlever is provided for pivoting the bolt, which is connected to the boltat a rear portion thereof. Depending on the length of the pivot lever acorrespondingly great torque can be applied in a simple manner whichproves to be of advantage for a reliable locking. The pivot lever can bedesigned both for manual operation and for an operation by means of aremote-controlled adjusting member.

Furthermore, according to the invention it is preferred that the lockingelement is supported on the sliding element in a radially movable andresilient manner. During the use of drill rod elements considerablesigns of wear, such as notches and deformations may occur, which onlypermit large-tolerance fits. In addition, there is the risk that e.g.soil material and rock can gather on the connecting portion of the drillrod so that a locking is only possible with great difficulty. Thespecific movable and resilient support of the locking element on thesliding element itself allows for a certain compensation, so that a goodlocking is ensured in these cases, too.

For a good rotational connection provision is made according to theinvention for axial ribs to be arranged on an inner side of thereceiving socket, which can be brought into engagement withcorresponding axial grooves of the connecting portion in order toproduce a rotational connection. In particular, this can be a keywayprofile. Through an axial sliding into one another a stable andextremely fixed rotational connection is thus produced. In such case itis possible that the locking element only ensures an axial locking. Therecess in the connecting portion can be a circumferential groove in thiscase, more particularly a rectangular groove, into which a correspondingrectangular profile of the locking element engages.

For an especially stable connection it is of advantage in accordancewith the invention that three locking devices are provided, which arearranged in an evenly distributed manner at the outer circumference ofthe receiving socket.

By preference, the coupling device according to the invention isemployed in a drilling apparatus having a drill drive for driving adrill rod.

Advantageously, the receiving socket is fixed to the output shaft of thedrill drive. In earth drilling apparatuses the output shaft usuallyprojects downwards so that the coupling device according to theinvention is arranged below the drill drive.

Furthermore, provision is made in accordance with the invention for thedrill drive to be supported on a carriage that is guided in a movablemanner on a mast. In this arrangement the coupling device in accordancewith the invention can be adjusted together with the carriage along themast so that when a new drill rod element is installed the couplingdevice provides for a quick and reliable connection between the upperconnecting portion of the newly installed drill rod and the drill drive.

The invention will be described further by way of embodiments, which areshown schematically in the accompanying drawings, wherein:

FIG. 1 shows a partially sectional view of a coupling device accordingto the invention in the release position;

FIG. 2 shows a partial view of the coupling device in accordance withFIG. 1 in the locking position;

FIG. 3 shows a side view of the coupling device of FIG. 1 and FIG. 2;

FIG. 4 shows a connecting portion of a drill rod and

FIG. 5 shows a partial view of a drilling apparatus with the couplingdevice according to the invention.

The construction and function of a coupling device according to theinvention will be described by way of FIGS. 1 to 3. The coupling device10 has a sleeve-shaped receiving socket 12, on the inner side of whichaxial ribs 28 are arranged for forming a keyway profile. On the outerside three locking devices 14 are arranged, which are mutually offset by120°. Each locking device 14 comprises a sleeve-shaped housing 18, inwhich an approximately rectangular locking element 16 is supported in amovable manner. The front of the rectangular locking element 16 has aconcave design to match the connecting portion to be locked. Moreover, acylindrical, bolt-shaped sliding element 20 is supported in the housing18 in an axially adjustable and pivotable manner. In the housing 18 anobliquely extending groove is applied that forms a slotted link 24. Acam 22 engages into the slotted link 24, which is arranged in a fixedmanner on the bolt-shaped sliding element 20. By means of a pivot lever26 fixed at the end of the sliding element 20 that projects from thehousing 18 the sliding element can be pivoted by 180° in the presentembodiment. Due to the interaction between the cam 22 and the slottedlink 24 the sliding element is moved axially. As a result, the lockingelement 16 is adjusted from a retracted release position shown in FIG. 1into a locking position according to FIG. 2.

The locking element 16 is resiliently supported on the sliding element20. To this end the locking element 16 has a central bore 30 and thesliding element 20 has a central pin 32. Between the bore 30 and the pin32 a helical spring 34 is arranged which pushes the sliding element 20and the locking element 16 apart from each other. To delimit the slidingpath a screw bolt 36 with a stop nut is arranged.

In FIG. 4 a connecting portion 62 is shown schematically, which can bewelded to the free end of a drill rod. The connecting portion 62 hasaxial grooves 66 that correspond to the axial ribs 28 on the inner sideof the receiving socket 12 so as to form a keyway connection. Forengagement into the locking element 16 an annular groove is formed as arecess 64 on the connecting portion 62. The width of the groovecorresponds to the width of the locking elements 16 so that they canengage in the recess 64 to produce an axial locking.

In FIG. 5 the arrangement of the coupling device 10 according to theinvention on a drilling apparatus 70 is shown. The drilling apparatus 70has a mast 78, along which a carriage 76 is guided and driven in amovable manner. On the carriage a drill drive 72 is supported thatconsists of a motor and a flanged-on gear. The receiving socket 12 ofthe coupling device 10 is welded to an output shaft 74 of the drilldrive 72. For the coupling of a drill rod 60 it has a connecting portion62 that has been described earlier on in conjunction with FIG. 4. Arotationally fixed connection is achieved by the mutually correspondingkeyway profiles, whereas an axial locking is achieved through thelocking elements 16 of the coupling device 10.

1. Coupling device for drill rods comprising a receiving socket for receiving a connecting portion of the drill rod, wherein at least one locking device with a locking element is provided, which is supported in an adjustable manner between a release position and a locking position, in which the locking element engages into a corresponding recess of the connecting portion.
 2. Coupling device according to claim 1, wherein the locking device has a housing arranged on the outer side of the receiving socket and in that a sliding element is supported in the housing for adjusting the locking element.
 3. Coupling device according to claim 2, wherein the sliding element is designed as a pivotably supported bolt having a cam, which engages into an obliquely extending slotted link in the housing.
 4. Coupling device according to claim 3, wherein a pivot lever is provided for pivoting the bolt, which is connected to the bolt at a rear portion thereof.
 5. Coupling device according to claim 1, wherein the locking element is supported on the sliding element in a radially movable and resilient manner.
 6. Coupling device according to claim 1, wherein on an inner side of the receiving socket axial ribs are arranged, which can be brought into engagement with corresponding axial grooves of the connecting portion in order to produce a rotational connection.
 7. Coupling device according to claim 1, wherein three locking devices are provided, which are arranged in an evenly distributed manner at the outer circumference of the receiving socket.
 8. Drilling apparatus comprising a drill drive for driving a drill rod, wherein a coupling device according to claim 1 is provided.
 9. Drilling apparatus according to claim 8, wherein the receiving socket is fixed to the output shaft of the drill drive.
 10. Drilling apparatus according to claim 8, wherein the drill drive is supported on a carriage which is guided in a movable manner on a mast. 